1. Field of the Invention
The invention relates to a light generator, more particularly to a light generator for a rotatable object.
2. Description of the Related Art
Referring to FIG. 1, a conventional hubcap is shown to include a cap body 10 formed with a plurality of vent holes 101, an impeller 11 formed with a plurality of blades 111, a permanent magnet 12, a coil device 13 and a lamp set 14 connected electrically to the coil device 13. When the cap body 10 rotates with a vehicle wheel (not shown), air passes through the vent holes 101 and pushes the blades 111 of the impeller 11 so as to drive the impeller 11 and the magnet 12 to rotate relative to the coil device 13, thereby inducing electrical currents in the coil device 13 that are provided to the lamp set 14 so as to enable the lamp set 14 to generate a light output. However, since the impeller 11 is driven by the air that passes through the vent holes 101, when the cap body 10 rotates slowly or when the vent holes 101 are blocked, the air flow will be insufficient to rotate the impeller 11, thereby resulting in a poor light generating effect.
Therefore, the object of the present invention is to provide a light generator for a rotatable object that can overcome the aforesaid drawback associated with the prior art.
According to the present invention, a light generator comprises:
a generator housing adapted to be secured to a rotatable object for co-rotation therewith, the generator housing having a front housing part, a rear housing part, and an axle hole that extends from the front housing part through the rear housing part;
an axle mounted rotatably in the axle hole and having a coupling end that extends out of the axle hole at the rear housing part;
a magnet disposed in the generator housing and mounted co-rotatably on the axle;
a coil device mounted in the generator housing and including a spool that surrounds the magnet, a coil wound around the spool, and a pair of conductive caps capped on an assembly of the spool and the coil, each of the conductive caps being connected electrically to a respective end of the coil;
a lamp unit mounted on the generator housing and connected electrically to the conductive caps of the coil device; and
a resistance unit mounted on the coupling end of the axle to resist axial rotation of the axle.
Rotation of the generator housing with the rotatable object results in rotation of the coil device relative to the magnet, thereby inducing electrical currents in the coil device that are provided to the lamp unit so as to enable the lamp unit to generate a light output.